Systems have been proposed for forming stacks of thick-butt shingles in which every other shingle in the stack has its thick portion alternating with the thin portion of the next adjacent shingle. In particular, one system receives pairs of shingles formed by a shingle laminating apparatus. These shingle pairs are made by diverting every other shingle as they are produced by the shingle laminating apparatus, accelerating this shingle using a belt-type conveyor, and sliding the accelerated shingle on a U-shaped chute, thus inverting this shingle end for end. The thus accelerated and inverted shingle arrives at a collator about the same time a non-inverted shingle arrives to form a shingle pair. This shingle pair is combined with other shingle pairs to form a stack of shingles which, as is the practice, is subsequently wrapped in bundle form for easy shipping and ultimate installation on a roof. However, the accelerated (and inverted) shingle was subject to damage on being received in the shingle pair collator. Also, the U-shaped chute encountered a great deal of wear since such laminated shingles are coated with a mineral aggregate weather surface which is by nature very abrasive in character.
Thus there remained in the prior art the need for an apparatus which could receive thick-butt, laminated shingles at a high sequential rate and yet successfully invert such shingles with little or no damage, and subsequently form bundles of inverted and noninverted shingles for subsequent packaging.